About this Abstract |
Meeting |
2023 TMS Annual Meeting & Exhibition
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Symposium
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Additive Manufacturing Fatigue and Fracture: Effects of Surface Roughness, Residual Stress, and Environment
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Presentation Title |
Defect-sensitive Fatigue Design in Additive Manufacturing: Flaw Size Effects in Ultrasonic Fatigue of Laser Powder Bed Fabricated Al-10Si-Mg Alloys |
Author(s) |
Anthony G. Spangenberger, Timothy D. Piette, Bernd Schönbauer, Diana A. Lados |
On-Site Speaker (Planned) |
Anthony G. Spangenberger |
Abstract Scope |
Additive manufactured (AM) materials frequently contain process-specific flaws that can result in early fatigue crack initiation and reduced fatigue lives. A quantitative understanding of the relationship between defect size and fatigue strength is therefore critical to design structural AM components. Fatigue testing of laser powder bed (LPB) Al-10Si-Mg specimens with polished surfaces and small drilled holes was conducted in the very-high cycle regime using ultrasonic frequencies. Fatigue strength sensitivity to initial flaw size was exhibited both by cracks naturally initiated from lack-of-fusion pores in smooth specimens and those with artificial flaws. Comparison with the Murakami model indicates that adequate fatigue strength predictions are made for both natural and artificial flaws. Complementary near-threshold ultrasonic fatigue crack growth tests were further conducted to establish an upper bound on the defect size sensitivity of the fatigue strength (long crack growth threshold). Recommendations will be made for fatigue design using fracture mechanics-driven methodologies. |
Proceedings Inclusion? |
Planned: |